The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingFront airbag sensor lh circuit malfunction
Description
The front airbag sensor lh consists of the diagnostic circuit, the frontal
deceleration sensor, etc.
If the center airbag sensor receives signals from the frontal deceleration
sensor, it determines whether or
not the srs should be activated.
Dtc b1615/14 is recorded when a ma ...
Dtc check / clear
Check dtc (using sst (check wire))
Check the dtcs (present trouble code).
Turn the ignition switch on, and wait for
approximately 60 seconds.
Using sst, connect terminals 13(tc) and 4(cg)
of the dlc3.
Sst 09843-18040
Notice:
Connect the terminals to the correct
positio ...
Alarm
The alarm uses light and
sound to give an alert when
an intrusion is detected.
The alarm is triggered in the
following situations when
the alarm is set:
Vehicles without smart key
system: A locked door is
unlocked or opened in any
way other than using the
wireless remote control or
key. (The ...